// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stddef.h>
#include <stdint.h>

#include "base/debug/proc_maps_linux.h"
#include "base/files/file_path.h"
#include "base/macros.h"
#include "base/path_service.h"
#include "base/strings/stringprintf.h"
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
#include "base/threading/platform_thread.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace base {
namespace debug {

    TEST(ProcMapsTest, Empty)
    {
        std::vector<MappedMemoryRegion> regions;
        EXPECT_TRUE(ParseProcMaps("", &regions));
        EXPECT_EQ(0u, regions.size());
    }

    TEST(ProcMapsTest, NoSpaces)
    {
        static const char kNoSpaces[] = "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/cat\n";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(kNoSpaces, &regions));
        ASSERT_EQ(1u, regions.size());

        EXPECT_EQ(0x00400000u, regions[0].start);
        EXPECT_EQ(0x0040b000u, regions[0].end);
        EXPECT_EQ(0x00002200u, regions[0].offset);
        EXPECT_EQ("/bin/cat", regions[0].path);
    }

    TEST(ProcMapsTest, Spaces)
    {
        static const char kSpaces[] = "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/space cat\n";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(kSpaces, &regions));
        ASSERT_EQ(1u, regions.size());

        EXPECT_EQ(0x00400000u, regions[0].start);
        EXPECT_EQ(0x0040b000u, regions[0].end);
        EXPECT_EQ(0x00002200u, regions[0].offset);
        EXPECT_EQ("/bin/space cat", regions[0].path);
    }

    TEST(ProcMapsTest, NoNewline)
    {
        static const char kNoSpaces[] = "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/cat";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_FALSE(ParseProcMaps(kNoSpaces, &regions));
    }

    TEST(ProcMapsTest, NoPath)
    {
        static const char kNoPath[] = "00400000-0040b000 rw-p 00000000 00:00 0 \n";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(kNoPath, &regions));
        ASSERT_EQ(1u, regions.size());

        EXPECT_EQ(0x00400000u, regions[0].start);
        EXPECT_EQ(0x0040b000u, regions[0].end);
        EXPECT_EQ(0x00000000u, regions[0].offset);
        EXPECT_EQ("", regions[0].path);
    }

    TEST(ProcMapsTest, Heap)
    {
        static const char kHeap[] = "022ac000-022cd000 rw-p 00000000 00:00 0 [heap]\n";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(kHeap, &regions));
        ASSERT_EQ(1u, regions.size());

        EXPECT_EQ(0x022ac000u, regions[0].start);
        EXPECT_EQ(0x022cd000u, regions[0].end);
        EXPECT_EQ(0x00000000u, regions[0].offset);
        EXPECT_EQ("[heap]", regions[0].path);
    }

#if defined(ARCH_CPU_32_BITS)
    TEST(ProcMapsTest, Stack32)
    {
        static const char kStack[] = "beb04000-beb25000 rw-p 00000000 00:00 0 [stack]\n";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(kStack, &regions));
        ASSERT_EQ(1u, regions.size());

        EXPECT_EQ(0xbeb04000u, regions[0].start);
        EXPECT_EQ(0xbeb25000u, regions[0].end);
        EXPECT_EQ(0x00000000u, regions[0].offset);
        EXPECT_EQ("[stack]", regions[0].path);
    }
#elif defined(ARCH_CPU_64_BITS)
    TEST(ProcMapsTest, Stack64)
    {
        static const char kStack[] = "7fff69c5b000-7fff69c7d000 rw-p 00000000 00:00 0 [stack]\n";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(kStack, &regions));
        ASSERT_EQ(1u, regions.size());

        EXPECT_EQ(0x7fff69c5b000u, regions[0].start);
        EXPECT_EQ(0x7fff69c7d000u, regions[0].end);
        EXPECT_EQ(0x00000000u, regions[0].offset);
        EXPECT_EQ("[stack]", regions[0].path);
    }
#endif

    TEST(ProcMapsTest, Multiple)
    {
        static const char kMultiple[] = "00400000-0040b000 r-xp 00000000 fc:00 794418 /bin/cat\n"
                                        "0060a000-0060b000 r--p 0000a000 fc:00 794418 /bin/cat\n"
                                        "0060b000-0060c000 rw-p 0000b000 fc:00 794418 /bin/cat\n";

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(kMultiple, &regions));
        ASSERT_EQ(3u, regions.size());

        EXPECT_EQ(0x00400000u, regions[0].start);
        EXPECT_EQ(0x0040b000u, regions[0].end);
        EXPECT_EQ(0x00000000u, regions[0].offset);
        EXPECT_EQ("/bin/cat", regions[0].path);

        EXPECT_EQ(0x0060a000u, regions[1].start);
        EXPECT_EQ(0x0060b000u, regions[1].end);
        EXPECT_EQ(0x0000a000u, regions[1].offset);
        EXPECT_EQ("/bin/cat", regions[1].path);

        EXPECT_EQ(0x0060b000u, regions[2].start);
        EXPECT_EQ(0x0060c000u, regions[2].end);
        EXPECT_EQ(0x0000b000u, regions[2].offset);
        EXPECT_EQ("/bin/cat", regions[2].path);
    }

    TEST(ProcMapsTest, Permissions)
    {
        static struct {
            const char* input;
            uint8_t permissions;
        } kTestCases[] = {
            { "00400000-0040b000 ---s 00000000 fc:00 794418 /bin/cat\n", 0 },
            { "00400000-0040b000 ---S 00000000 fc:00 794418 /bin/cat\n", 0 },
            { "00400000-0040b000 r--s 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::READ },
            { "00400000-0040b000 -w-s 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::WRITE },
            { "00400000-0040b000 --xs 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::EXECUTE },
            { "00400000-0040b000 rwxs 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::READ | MappedMemoryRegion::WRITE | MappedMemoryRegion::EXECUTE },
            { "00400000-0040b000 ---p 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::PRIVATE },
            { "00400000-0040b000 r--p 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::READ | MappedMemoryRegion::PRIVATE },
            { "00400000-0040b000 -w-p 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::WRITE | MappedMemoryRegion::PRIVATE },
            { "00400000-0040b000 --xp 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::EXECUTE | MappedMemoryRegion::PRIVATE },
            { "00400000-0040b000 rwxp 00000000 fc:00 794418 /bin/cat\n",
                MappedMemoryRegion::READ | MappedMemoryRegion::WRITE | MappedMemoryRegion::EXECUTE | MappedMemoryRegion::PRIVATE },
        };

        for (size_t i = 0; i < arraysize(kTestCases); ++i) {
            SCOPED_TRACE(
                base::StringPrintf("kTestCases[%zu] = %s", i, kTestCases[i].input));

            std::vector<MappedMemoryRegion> regions;
            EXPECT_TRUE(ParseProcMaps(kTestCases[i].input, &regions));
            EXPECT_EQ(1u, regions.size());
            if (regions.empty())
                continue;
            EXPECT_EQ(kTestCases[i].permissions, regions[0].permissions);
        }
    }

#if defined(ADDRESS_SANITIZER)
    // AddressSanitizer may move local variables to a dedicated "fake stack" which
    // is outside the stack region listed in /proc/self/maps. We disable ASan
    // instrumentation for this function to force the variable to be local.
    __attribute__((no_sanitize_address))
#endif
    void
    CheckProcMapsRegions(const std::vector<MappedMemoryRegion>& regions)
    {
        // We should be able to find both the current executable as well as the stack
        // mapped into memory. Use the address of |exe_path| as a way of finding the
        // stack.
        FilePath exe_path;
        EXPECT_TRUE(PathService::Get(FILE_EXE, &exe_path));
        uintptr_t address = reinterpret_cast<uintptr_t>(&exe_path);
        bool found_exe = false;
        bool found_stack = false;
        bool found_address = false;

        for (size_t i = 0; i < regions.size(); ++i) {
            if (regions[i].path == exe_path.value()) {
                // It's OK to find the executable mapped multiple times as there'll be
                // multiple sections (e.g., text, data).
                found_exe = true;
            }

            // Valgrind uses its own allocated stacks instead of the kernel-provided
            // stack without letting the kernel know via prctl(PR_SET_MM_START_STACK).
            // Depending on which kernel you're running it'll impact the output of
            // /proc/self/maps.
            //
            // Prior to version 3.4, the kernel completely ignores other stacks and
            // always prints out the vma lying within mm->start_stack as [stack] even
            // if the program was currently executing on a different stack.
            //
            // Starting in 3.4, the kernel will print out the vma containing the current
            // stack pointer as [stack:TID] as long as that vma does not lie within
            // mm->start_stack.
            //
            // Because this has gotten too complicated and brittle of a test, completely
            // ignore checking for the stack and address when running under Valgrind.
            // See http://crbug.com/431702 for more details.
            if (!RunningOnValgrind() && regions[i].path == "[stack]") {
                EXPECT_GE(address, regions[i].start);
                EXPECT_LT(address, regions[i].end);
                EXPECT_TRUE(regions[i].permissions & MappedMemoryRegion::READ);
                EXPECT_TRUE(regions[i].permissions & MappedMemoryRegion::WRITE);
                EXPECT_FALSE(regions[i].permissions & MappedMemoryRegion::EXECUTE);
                EXPECT_TRUE(regions[i].permissions & MappedMemoryRegion::PRIVATE);
                EXPECT_FALSE(found_stack) << "Found duplicate stacks";
                found_stack = true;
            }

            if (address >= regions[i].start && address < regions[i].end) {
                EXPECT_FALSE(found_address) << "Found same address in multiple regions";
                found_address = true;
            }
        }

        EXPECT_TRUE(found_exe);
        if (!RunningOnValgrind()) {
            EXPECT_TRUE(found_stack);
            EXPECT_TRUE(found_address);
        }
    }

    TEST(ProcMapsTest, ReadProcMaps)
    {
        std::string proc_maps;
        ASSERT_TRUE(ReadProcMaps(&proc_maps));

        std::vector<MappedMemoryRegion> regions;
        ASSERT_TRUE(ParseProcMaps(proc_maps, &regions));
        ASSERT_FALSE(regions.empty());

        CheckProcMapsRegions(regions);
    }

    TEST(ProcMapsTest, ReadProcMapsNonEmptyString)
    {
        std::string old_string("I forgot to clear the string");
        std::string proc_maps(old_string);
        ASSERT_TRUE(ReadProcMaps(&proc_maps));
        EXPECT_EQ(std::string::npos, proc_maps.find(old_string));
    }

    TEST(ProcMapsTest, MissingFields)
    {
        static const char* const kTestCases[] = {
            "00400000\n", // Missing end + beyond.
            "00400000-0040b000\n", // Missing perms + beyond.
            "00400000-0040b000 r-xp\n", // Missing offset + beyond.
            "00400000-0040b000 r-xp 00000000\n", // Missing device + beyond.
            "00400000-0040b000 r-xp 00000000 fc:00\n", // Missing inode + beyond.
            "00400000-0040b000 00000000 fc:00 794418 /bin/cat\n", // Missing perms.
            "00400000-0040b000 r-xp fc:00 794418 /bin/cat\n", // Missing offset.
            "00400000-0040b000 r-xp 00000000 fc:00 /bin/cat\n", // Missing inode.
            "00400000 r-xp 00000000 fc:00 794418 /bin/cat\n", // Missing end.
            "-0040b000 r-xp 00000000 fc:00 794418 /bin/cat\n", // Missing start.
            "00400000-0040b000 r-xp 00000000 794418 /bin/cat\n", // Missing device.
        };

        for (size_t i = 0; i < arraysize(kTestCases); ++i) {
            SCOPED_TRACE(base::StringPrintf("kTestCases[%zu] = %s", i, kTestCases[i]));
            std::vector<MappedMemoryRegion> regions;
            EXPECT_FALSE(ParseProcMaps(kTestCases[i], &regions));
        }
    }

    TEST(ProcMapsTest, InvalidInput)
    {
        static const char* const kTestCases[] = {
            "thisisal-0040b000 rwxp 00000000 fc:00 794418 /bin/cat\n",
            "0040000d-linvalid rwxp 00000000 fc:00 794418 /bin/cat\n",
            "00400000-0040b000 inpu 00000000 fc:00 794418 /bin/cat\n",
            "00400000-0040b000 rwxp tforproc fc:00 794418 /bin/cat\n",
            "00400000-0040b000 rwxp 00000000 ma:ps 794418 /bin/cat\n",
            "00400000-0040b000 rwxp 00000000 fc:00 parse! /bin/cat\n",
        };

        for (size_t i = 0; i < arraysize(kTestCases); ++i) {
            SCOPED_TRACE(base::StringPrintf("kTestCases[%zu] = %s", i, kTestCases[i]));
            std::vector<MappedMemoryRegion> regions;
            EXPECT_FALSE(ParseProcMaps(kTestCases[i], &regions));
        }
    }

    TEST(ProcMapsTest, ParseProcMapsEmptyString)
    {
        std::vector<MappedMemoryRegion> regions;
        EXPECT_TRUE(ParseProcMaps("", &regions));
        EXPECT_EQ(0ULL, regions.size());
    }

    // Testing a couple of remotely possible weird things in the input:
    // - Line ending with \r\n or \n\r.
    // - File name contains quotes.
    // - File name has whitespaces.
    TEST(ProcMapsTest, ParseProcMapsWeirdCorrectInput)
    {
        std::vector<MappedMemoryRegion> regions;
        const std::string kContents = "00400000-0040b000 r-xp 00000000 fc:00 2106562 "
                                      "               /bin/cat\r\n"
                                      "7f53b7dad000-7f53b7f62000 r-xp 00000000 fc:00 263011 "
                                      "       /lib/x86_64-linux-gnu/libc-2.15.so\n\r"
                                      "7f53b816d000-7f53b818f000 r-xp 00000000 fc:00 264284 "
                                      "        /lib/x86_64-linux-gnu/ld-2.15.so\n"
                                      "7fff9c7ff000-7fff9c800000 r-xp 00000000 00:00 0 "
                                      "               \"vd so\"\n"
                                      "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 "
                                      "               [vsys call]\n";
        EXPECT_TRUE(ParseProcMaps(kContents, &regions));
        EXPECT_EQ(5ULL, regions.size());
        EXPECT_EQ("/bin/cat", regions[0].path);
        EXPECT_EQ("/lib/x86_64-linux-gnu/libc-2.15.so", regions[1].path);
        EXPECT_EQ("/lib/x86_64-linux-gnu/ld-2.15.so", regions[2].path);
        EXPECT_EQ("\"vd so\"", regions[3].path);
        EXPECT_EQ("[vsys call]", regions[4].path);
    }

} // namespace debug
} // namespace base
